Researchers at Northwestern University have used Blu-ray discs — of Jackie Chan’s seminal Police Story 3: Supercop, to be exact — to increase the efficiency of solar panels by a massive 22%.

This one’s a bit crazy, but stick with me. Blu-ray discs, like CDs and DVDs before them, consist of a thin layer — or layers — of recording medium sandwiched between two bits of plastic. Data is stored on this medium in a series of pits — small indentations — that are about 75nm long. To read the data, a laser is bounced off the recording medium — where the medium is smooth and untouched (usually referred to as islands), the laser light bounces straight back into a sensor; where the pits are, the laser is reflected differently. Thus, binary data can be stored and read.

In the case of Blu-ray, the binary data isn’t just burnt directly to the disc — compression is applied, and error control codes are added so that data can be recovered in the case of light scratches. Because the error control codes are applied every few bytes, the end result is a disc covered in quasi-random pits and islands that have a recurring pattern every 150 to 525 nanometers. (The iridescence — rainbow effect — of optical discs is caused by this repeating pattern, in case you wondered.)

As it turns out, these two characteristics — a quasi-random pattern, repeating every 150 to 525nm — are almost perfectly tuned for trapping photons in the visible light and near-infrared spectrum. One of the main reasons that current solar cells aren’t that efficient is because many photons simply reflect off the panel, rather than being converted into electrons. You can probably see where this is going.

Nanopatterning a photovoltaic cell, using a Blu-ray’s recording medium as a template

Part of the solar cell has been treated with the Blu-ray nanopattern mold, the other part hasn’t

To increase the efficiency of a solar panel by 22%, the researchers at Northwestern bought a copy of Police Story 3: Supercop on Blu-ray; removed the top plastic layer, exposing the recording medium beneath; cast a mold of the quasi-random pattern; and then used the mold to create a photovoltaic cell with the same pattern. As you can see in the image above, this process actually makes the nanopatterned solar cell have the same iridescence as a Blu-ray disc. [Research paper: doi:10.1038/ncomms6517]

The end result is a solar panel that has a quantum efficiency of around 40% — up about 22% from the non-patterned solar panel. As you can see in the graph above, the nanopatterning increases the solar panel’s absorption and efficiency across the entire range of 400-700nm wavelengths (visible to near infrared).

Moving forward, can we expect the price of mediocre Jackie Chan movies to soar? Probably not. Any Blu-ray disc should work — and anyway, the more important takeaway here is that we should start nanopatterning our solar panels immediately. It just so happens that taking a mold of a Blu-ray disc is a cheap and easy way to get your hands on a good quasi-random nanopattern — but in the future, the patterning could be produced directly, without the Blu-ray intermediate.

Tagged In

Haha, nice informative, though very tongue in cheek article. Would love to see this deployed in the next few years.

Felix Gill

so what you are saying is that this professor is making illegal exact copies of a movie and not paying royalties…

craig calkins

You beat me to the punch line!

Rartemass

People have been ripping off Jackie Chan for years. The opening of Tango and Cash was an almost motion for motion rip off of a scene in Police Story, including the cinematography. Brandon Lee ripped off several scenes across his movies in similar exacting ways.
To be fair Jacki Chan has ripped off some ideas too. Twin Dragons is the same premise as Van Damme’s Double Impact, but done in a much better and comedic manner.

MisterBlat

“It just so happens that taking a mold of a Blu-ray disc is a cheap and easy way to get your hands on a good quasi-random nanopattern”

Until the MPAA lawyers and Taylor Swift get involved…

“Well, ya know all ya’ll need is a big ol’ space laser and the whole galaxy can listen to ‘Shake It Off’ for free! Told y’all I don’t want to be no part of no grand exper’ment…”

bob lebart

Maybe roofs will look cool covered in dvds eh…
on a more serious note, this discovery is HUGE. If past R&D of solar panels
missed 22% efficiency right under their noses (and from old tech!), it kind of
makes one wonder what else science is missing that is just as obvious. Of
course, E=MC2 seems obvious now, after that white-haired guy figured it out.

JD Rahman

Leslie Nielsen was an amazing person. I miss him too

bob lebart

:-) Lmao!

Marco

You think he’s talking about Leslie Nielsen? Surely you can’t be serious. =P

bob lebart

but I WAS talking about Leslie Nielsen- If he hadn’t discovered relativity, he would never have been able to fly to that forbidden planet !

davedsone

I AM serious. And don’t call me Shirley.

Marcelo

Simple technologies helping solve energy problems.

http://www.brainsnacksdaily.com/ Wait

“Moving forward, can we expect the price of mediocre Jackie Chan movies to soar? Probably not.”

OK, so now the plan is:
1. buy up solar panel wafers,
2. cut/grind them into disks and
3. burn them on my BD burner.
(4. ???, 5. PROFIT!)

Shawn

I”m waiting to hear about the copyright infringment lawsuit or the lawsuit about breaking the dmca by copying the encoding with out permission

gbarth

Are we talking an extra 22% efficiency here (so round 40% efficient panels) or just an increase of 22% (24% efficient panels)?

openeyes00

I think they are saying a move up from 18% to 40% or at least I hope so. This is such a big deal if it is the case, more than twice the current efficiency and a game changer you would have thought.

openeyes00

I read on another site it gives a 12% improvement in conversion efficiency, every little improvement will help though if the pattern process is cheap enough. My fantasy is that 80% conversion will be one day possible by absorbing the whole light spectrum.

I did like the idea of solar roads until I understood that having panels flat instead of at an angle like on a roof reduced electric output several fold, but on the bright side there are still plenty of empty roofs.

http://www.mrseb.co.uk/ Sebastian Anthony

I’m pretty sure it’s from ~33% total efficiency to ~40% total efficiency — so an improvement of about 20%. (40% for a solar cell is pretty darn good.)

The actual article does say that “The absorption of the Blu-ray-imprinted cell is
significantly enhanced by 21.8% over the entire absorption
profile.” (The increase in absorption is particulary high in the wavelengths where the material normally absorbs weakly.) However, there are various further steps before you get to output, and they conclude by saying the whole process is “eventually leading to a power conversion efficiency enhancement of 11.9%”

http://www.ultimatexbmc.com/ Ultimatexbmc.com

Bruce Lee disks get 100%

mrseanpaul81

chuck norris disks gets 1000% efficiency!

MrCambron

over 9000!

g0rl0k

Next time: try with Sunshine (2007). Kids: don’t do it in your house.

Alumine

If they use a Chuck Norris Blu-Ray they would have achieved an 100% increase.

Dustymack

I bet a Chuck Norris disk would raise it 300%.

adele hanks

What about Bruce lee

Michael R

Literally Lol’d at the end. It’s not often that I do that.

Mo Friedrich

I wonder, if this exact pattern is pretty good, couldn’t we let some supercomputer figure out a pattern that is pretty damn perfect? Maybe even 60% would be possible if more of the spectrum could be caught.
40% efficiency solar panels will change a lot, anyway – this could finally lead to broad adoption in energy generation in favor to coal, and I am sure NASA will find a use for them too. Exciting times!

mrseanpaul81

I don’t know enough to say for sure but my wild guess would be because the standard model is incomplete and quantum effects involved are humongous in quantity and computing power to sweep over them, it would take a supercomputer many many many years to find an optimum solution (again, just a guess, anybody that knows way more about this, please feel free to correct me)

http://www.korioi.net/ Korios

If these solar cells have a ~40% efficiency with just a single junction (layer), using them in double and triple junctions could presumably provide an efficiency all the way up to 65-70%, much higher than the current ~45% of top, ultra expensive, military grade multi-junction cells, while being cheaper. Having a ~40% efficiency “floor” and going all the way to the maximum theoretical efficiency for top cells would mean a massive boost in solar panel usage. I just hope this tech does not join all the other tens of inventions that have been shelved because the market thought they would generate less profit by adopting them..

Mo Friedrich

If you are correct, that will revolutionize the whole energy market.. For the first time, green energy is within our reach!

Teodor Jovanovski

So……….If this is real, the prices of solar panels will drop? And efficiency increase?
I’ll study Electrical engineering and i am EXCITED!

Bodga

I think that Solar3D figured this out years ago..

KÆsmr Øø

Live demonstrations please

Alantar

I am imagining archaeologists from the future, after a collapse of civilization, digging up solar panels, carefully piecing together whatever data they can find, and finally basing their entire interpretation of pre-collapse civilization from a few recovered scenes from a Jackie Chan movie.

David King

Very nice article! It was a good read, thanks Sebastian!

http://bit.ly/solar-supply Mr. O

This article has my head spinning like a blu ray

…like, so energy harmonizes with how information is best stored, aaaaand drum roll for the “e=mc^2” connecting energy/matter to information

http://blog.notdot.net/ Nick Johnson

“The end result is a solar panel that has a quantum efficiency of around 40% — up about 22% from the non-patterned solar panel.”

Assuming the standard solar panel was 18% efficient, this isn’t an improvement of 22% – it’s a massive improvement of 120%!

MichaelZWilliamson

I wonder what Chuck Norris Blu Rays will do.

ronch

Why did this article go to so much trouble trying to explain why this happens? I’ll tell you why this trick works: It’s because of all the KUNG-FU FIGHTING!!!

actionjksn

If the surface of a Blue Ray just happens to work that well, then I suspect that based on what they learned here, they can design a similar but improved pattern that does what this does only better. Just study what is happening with this and tweak it to get even more performance.

They also may be able to laser etch this type of pattern into existing solar panels to retrofit this technology to the old design.

This technology should also be able to be implemented into new solar panels without requiring years of development. This should be getting put into use in the real world almost immediately. There’s no excuse not to and they can add further improvements down the road.

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